Cheaper Big-Screen OLEDs

Cheaper Big-Screen OLEDs

Longer life: DuPont has developed longer-lasting OLED materials that can be printed using cheap, simple techniques to make displays like this one.

High-end displays made from organic materials are lightweight, energy efficient, and crisp–but it has proved difficult to manufacture them cheaply and durably.

Now the chemical giant DuPont is reporting the development of long-lasting organic-display materials that can be printed cheaply over large areas, much like ink. DuPont says that these materials can be used to make cheaper high-end displays with existing equipment, and the company says that it is in talks with display manufacturers to bring them to market.

Each pixel in an organic light-emitting diode (OLED) is made up of materials that emit red, green, and blue light in response to electrical stimulation via a thin-film transistor backplane.

OLED displays on the market today are made by depositing organic materials in a vapor through a mask. This setup ensures that differently colored subpixels are properly aligned, but the process is expensive, because some material inevitably gets lost, and difficult to do over large areas. For this reason, OLEDs have so far found their way into only a few products, including a Sony television and some Samsung cell phones.

An alternative approach is solution deposition, which involves printing liquid organic materials onto a surface. Several companies and university research groups have been trying to develop such printable OLED materials, but it’s difficult to make light-emitting materials that last long enough to bring them to market: the display quality tends to degrade too quickly.

“If one could get high performance from solution-deposition methods, it would be very attractive: it would solve the scaling issues” associated with making these displays, says Nick Colaneri, director of the Flexible Display Center at Arizona State University, in Tempe. “Now DuPont claims to have solved that problem.”